Portable scaffold unit



1954 w. J. s. JOHNSON PORTABLE SCAFFOLD UNIT Filed Sept. 15. 1947INVENTOR.

Patented Jan. 12, I954 UNITED STATES PATENT orries PORTABLE SCAFFOLDUNIT Wallacev J. S. Johnson, Berkeley,xCalif. Ap lic ion Sep ember 15,1947, sesame. 174,038

7 Claims. 1

The present invention pertains to scaffolds used by builders and thelike, and more particularly to scafiolds of the portable type.

It is an object of the present invention to provide an improved mannerof bracing a scaffold unit, and to facilitate assembling and dismantlingof diagonal braces to other parts comprising the scaffold unit.

Another object of the invention is to provide a locking mechanism forsecuring a diagonal brace to other parts of the scaffold unit, whichcannot be released inadvertently to allow disconnection or disengagementof the brace.

One form which the invention mayassume is exemplified in the followingdescription and illustrated by way of example inthe accompanyingdrawings, in which;

Fig. 1 is .a perspective view of a scaffold unit embodying one form ofthe present invention.-

Fig. 2 is a longitudinal section through the lower end of one of thediagonal braces, disclosing the elements for locking such brace to anend section of the scaffold unit.

Fig. 3 is a partial sectional and elevational view through the upper endof a diagonal brace disclosing the manner of securing it in lockedposition to an end section of the scaffold unit.

The general scaffold unit S is essentially the same as the, onedescribed in the application of Wallace J. S. Johnson and Thomas H.Harvey, Serial No. 678,790, filed June 24, 1946, which is now Patent.No. 2,438,173, dated March 23, 1948;

for Portable and Collapsible Scaffolding Unit.

As described in that application, the scaffold unit comprises an upperplatform. section l0, end:

sections I l, Ha and a. ladder or stairway section I2. In addition, thepresent scaffold-i unit includes one or more diagonalbraces. l3.Theplats. form section l comprises three parallel longitudinal framemembers l4, l5, I6, the outer frame members l4, l6 being located atopposite. sides of the platform-and on opposite 'sides'of' theintermediate frame member l5.

Each of the opposite ends of each frame member i4, i5, i6 is welded, orotherwise firmly secured, to a trunnion i1 rotatably mounted on an uppertransverse frame member it of an adjacent end or supporting section II,Ila, thus forming an articulated connection between the platform sectionI!) and the upper ends of the supporting or end sections H, Ha. Suitablecollars I9 are welded on the frame members of the end sections toprevent lateral movementor displacement of the frame members HI, [5, 16"

along the upper transverse members l8.

A fiat flooring 20- is secured on the platform section overlying one ofthe outer and the intermediate frame members It, I5. This flooring maybe of plywood, or any other suitable material of sufficient strength tosupport the weight of workmen, or to suit conditions to which thescaffold unit is to be subjected.

Each of the end or supporting frames or sections H, Ha, comprises, inaddition to its upper transverse frame member 18, a lower transverseframe member 2i and a pair of upright parallel supporting legs 22. Theupper frame members i8-are welded at theirends to vertical sockets.23-suitably secured; as by welding to the upper ends of the legs 22while the lower frame mem bers 21 are welded to collars 24 secured onthe lower portions of the legs, as by welding or the verse-member 'i8-ofthe other section II. These last-mentioned diagonal braces are arrangedoppositely :to the ladder brace l2;

As explained in the application above-referred to, upon removal of thediagonal braces l3 from the end sections, the end sections 1 5, Ha,platform sections Wand ladder sections 12 may be collapsed to acomparatively flat position by folding one end section H against oneside of the platform and ladder sections ill, i2 and the other endsection Ha against the other side of the platform and ladder sections,enabling the end, platform and ladder sections to be transportedconveniently as a unit. I

Each diagonal brace I3 includes a tubular member 26 having a hook .27 or21a secured to each end, the shank portion 28 of the hook being pilotedinto the end of the tubular member and the two parts then weldedtogether. A locating pin 29 is secured in the central portion of thehookand extends inwardly to its interior. Dis-. posed at an angle to thelocating pin is a locking its head 32 with an At the bottom end of thebrace [3, the locking pin 38 and the bore 3| in which it is slidable areso disposed on the shank that they occupy a generally vertical positionwhen the diagonal brace is secured to the lower transverse member 2| ofan end section I Hi. Such lower transverse member has a hole 34 adaptedto receive the locating pin 29 when the lower hook portion 21 of adiagonal brace is disposed thereover. This definitely determines theposition of the diagonal brace I3 longitudinally of the lower transversemember 2|. During placing of the hook portion over the lower transversemember, the locking pin 30 is retracted within the hook shank 28 untilthe locating pin 29 is disposed within the cooperable hole 34 on thelower transverse member 2| and the hook engaged fully around the latter,

whereupon the locking pin 30 is released for gravitational projectionfrom the shank hole 3| into a position adjacent the exterior of thelower transverse member 2|. It is evident that the locking pin 30, byextending across the open side of the hook 2'! and transversely acrossthe lower member 2|, prevents movement of the hook in a diagonallyupward direction, which would disengage it from the lower transversemember. Accordingly, the hook 21 is held from removal from the lowertransverse member 2| until the vertical locking pin 30 is moved upwardlywithin the shank 28 to a position clear of the lower transverse member,whereupon the hook portion 2'! of the diagonal brace l3 may be movedoutwardly to shift its locating pin 29 from its cooperable hole 34 anditself from the lower transverse member. 7

'The upper portion of each diagonal brace I3 is formed similarly to thelower portion by piloting the shank portion 28a of a hook within thediagonal tubular member 26 and welding the two parts together. The upperhook 21a is adapted to be engaged over the upper transverse member l8 ofthe opposite end section II of the scaffold unit, being provided with alocating pin 29a adapted to be received within a hole 34a in the uppertransverse member spaced from the leg 22 of the end sectionsubstantially the same distance as the corresponding hole 34 on thelower transverse member 2| of the other end section is spaced from itsadjacent leg 22. Instead of being disposed substantially vertically, asthe pin 30 at the lower end of the diagonal brace, the locking pin 30ais disposed in a generally hori-. zontal position, extending through a.hole 3la in the shank portion of the hook, with its head-32a engaging astop shoulder 33a in the shank, the pin 300. being urged to an outerposition by a spring 35 compressed between its head end 32a and aretainer 35 suitably secured to the shank.

In assembling the upper end of the brace l3 on the upper transversemember 18, the pin 30a is retracted against the force of the spring 35and the hook 21a placed around the transverse member l8 with thelocating pin 29c inserted within its cooperable upper transverse memberhole 34a. Thereafter, the pressure on the locating'pin 30a may bereleased to allow the spring 35 to project it outwardly under the uppertransverse member Ia and partially across the open side of the hook 21a.

It is apparent that the upper end of the brace cannot be removed fromits assembled relation on theupper transverse member l8, since themovement of the hook 21a diagonally from the latter isprevented byengagement of the pin 30a with the undersurface-oi the transverse memberl8.

The only way in which the hook can be dismantled from the uppertransverse member is to first retract the horizontal pin 300. againstthe spring force, which then permits disconnection and removal of thehook from the transverse member.

The ladder or stairway section l2, which also serves as a diagonalbrace, includes two parallel tubular ladder bars 31 to which steps orrungs 38 are welded. The upper ends of these ladder bars are secured totrunnions 39 rotatable on the upper transverse member [8 of one endsection Ha, their lower ends being secured to the lower transversemember 2| of the other end section H by providing a hook and pinarrangement on them substantially the same as on the lower ends of thediagonal braces l3.

By virtue of the construction of the diagonal braces 13, they may beassembled or secured rapidly to the upper and lower transverse membersl8, 2| of the end sections, with assurance that they cannot be removedinadvertently, in view of the locking action of the vertical andhorizontal pins 30, 30a. 7

In the event that a single scaffold unit is employed, the end of theflooring 20 of the platform is disposed sufficiently close to the upperhook end 21a of one of the diagonal braces as to prevent upward movementof such end from its cooperable upper transverse member l8, despiteretraction of the horizontal pin 38a. The clearance between the end offloor 20 and the uppermost portion of the hook 21a is relatively small,of the order of about which prevents disengagement of the brace I3 fromthe upper transverse member l8; so long as the flooring isin place.

A second scaffold unit T maybe disposed upon the first scaffold unit Sby piloting its legs 22 within the sockets 23 provided on the upper endsof the legs 22 of the first unit. The lower transverse member 2 of theupper unit will be disposed closely adjacent the upper hook ends 21a ofthe diagonal braces I3, with very little clearance therebetween.Accordingly, retraction of the horizontal pins 32a, with the upperscaffold unit T in place, still does not allow removal of the diagonalbraces I3, since attempts to elevate theirv hook ends will efiect theirengagement with the lower transverse members 2| of the upper unit, andpreclude their disconnection from the upper member l8 of the lower unitS. Accordingly, since the diagonal braces l3 cannot be removed, so longas an upper scaffold unit T is disposed upon a lower scafiold unit S,assurance is had against inadvertent collapsing of the latter.

It is, accordingly, apparent that an improved locking device for thebrace members of a scaffold unit has been provided, which enables thebraces to be assembled and dismantled from the unit very readily, andwhich cannot be inadvertently released to allow disconnection ordisengagement of the braces from its cooperable parts.

While I have illustrated and described my. invention in detail, it is tobe understood that various changes may be made therein by those skilledin the art without departing from the invention as defined in theappended claims.

Having thus described my invention, what 1 claim and desire to secure byLetters Patent is:

1. A scaffold structure, including a' lower scaffold unit having spacedend sections, each section including upper and lower transverse members,a diagonal brace extending between 2&65360:

said sections, said brace comprising hooks at its n s a hable to heu nertr n somomber of one section and the lower transverse member of theother section, and an upper scafiold unit similar to the lower unit andmounted upon said lower scaffold unit to dispose one ofits transversemembers in close proximity to the hook attachable to said uppertransverse member-to prevent disconnection of said upper hook therefrom,the shortest distance between said one transverse member of the upperunit and said hook being substantially less than the diameter of saidupper transverse member.

2. In a dismountable tubular scaflolding, a coupling comprising agenerally hook-shaped member adapted to be placed onto a tubular c f dmber. o p r ia l embr he: sam said hook-shaped member having a baseportion and spaced flanks, a locking pin rectilinearly retractablewithin one of said flanks and serving to at least partially bridge thegap between said flanks when in extended position, and arranged forautomatic retraction upon placement of the hook-shaped member on, andthe consequent pin engagement with, a tubular scaffold member, saidlocking pin having its axis extending outwardly in the same generaldirection as the hook-shaped member opens, but angularly to saiddirection so as to intersect the other flank if extended, so that thelocking pin is pushed inwardly by engagement with a tubular scafloldmember when the hook-shaped member is placed on the same, the angle madeby the axis of the locking pin with the direction in which thehookshaped member opens being in the neighborhood of a medial acuteangle, and a locating pin fixed to said base portion and extendinginwardly of said hook-shaped member to fit Within a mating hole of thetubular scaiiold member when the hook-shaped member is placed thereon.

3. A coupling device for dismountable scafiold units comprising agenerally hook-shaped member adapted to be placed onto a tubularscafiold member to partially embrace the same, said hookshaped memberhaving a base portion and spaced flanks, a locking pin rectilinearlyretractable Within one of said flanks and serving to at least partiallybridge the gap between said flanks when in extended position, andarranged for automatic retraction upon placement of the hock-shapedmember on, and the consequent pin engagement with, a tubular scaffoldmember, said locking pin having its axis extending outwardly in the samegeneral direction as the hook-shaped member opens, but angularly to saiddirection so as to intersect the other flank if extended, so that thelocking pin is pushed inwardly by engagement with a tubular scaffoldmember when the hook-shaped member is placed on the same, the angle madeby the axis of the locking pin with the direction in which thehookshaped member opens being in the nlegh-borhood of a medial acuteangle, spring means urging the pin outwardly, and means for limitingout- Ward movement of the pin.

4. In a dismountable scafiolding having tubular brace sections, acoupling comprising a body having a shank portion secured within an endof a tubular brace section in axial alignment therewith and providedwith a bore extending through the shank portion at an acute angle to theaxis of the brace, said bore opening outwardly at a point slightlyspaced from the end of the brace, a hook-shaped portion upon the bodyopening outwardly at right angles to the axis of the shank and brace andarrangedtoseatupon; a second tubular section disposed at right angles tothe brace section, interengageable pin. and, socket means upon the hookportion and the t bular s ct on. nga ed ther y. for p s tio ing: thecoupling longitudinally of said tubular sec: on nd p ev nting relativerotati n thereof. and latch means mounted, in the bore of the hank nd,operab e for releasably hold n the hoo r on, n s ated position upon thesec.- ond tubular section.

n, a dismo ntab e, scafio din having tub lar brace sections, a couplingcomprising a body having a shank portion secured within an end of atubular brace section in axial alignment therewith and provided with abore the shank portion at an acute angle to thefaxis of the brace, saidbore'opening outwardly at a point slightly spaced from the end of thebrace, a hook-shaped portion upon the body opening outwardly at rightangles to the axis of the shank and brace and arranged to seat upon asecond tubular section disposed at right angles to the brace section,interengageable pin and socket means upon the hook portion and thetubular section engaged thereby for positioning the couplinglongitudinally of said tubular section and preventing relative rotationthereof, a latch pin slidably mounted in the bore of the shank andextendable angularly partially across the open side of the hook portionin retaining engagement with the second tubular section, means limitingoutward movement of the pin, and a spring normally urging the latch pinoutwardly, the pin being disposed at an angle to the hook portion suchas to permit inward displacement of the pin by engagement with thesecond tubular section as the hook is moved to seating position thereonwhile requiring manual displacement of the pin to permit unseatingmovement or the hook.

6. In a dismountable tubular scafiold structure, a lower unit having atransverse member, a diagonal brace provided with a coupling memberdismountably engaging the tranverse member, said coupling member havinga hook portion seating upon the transverse member, interengaging pin andsocket means upon the hook portion and transverse member for positioningthe coupling upon the transverse member and preventing relative rotationthereof, spring actuated latch means carried by the coupling member atan angle permitting inward displacement by engagement with thetransverse member to permit movement of said member to seating positionand requiring manual displacement to permit outward movement of thetransverse member from its seated position, and an upper unit having atransverse member parallel to the transverse member of the lower unitand spaced therefrom to prevent displacement of the coupling membertherefrom while the scaffold units are in assembled relation.

7. A coupling member for detachably connecting tubular brace sections ofa dismountable scaffolding comprising a body having a hook-shapedportion opening laterally from one side of the body for detachablyengaging a tubular brace section, a shank extending axially from thehook portion and having a, shoulder providing a seat for the end of atubular brace section to be connected to a brace section engaged by thehook portion, said shank also having a bore extending through the shankat an acute angle from a point back of the shoulder to a pointpositioned outwardly from the shoulder; said bore opening adjacent theopen extending through.

side of thehook portion and having aeounter bore providing an internalshoulder, a latch pin slidably mounted "in the bore and extendahletherefrom at an acute angle partially across the open side of the hookportion, a shoulder upon the pin engageable with the internal shoulderfor seating the pin in latching position, and spring means normallyurging the pin to latching positio and displaceable by movement of thehook portion onto the brace section to admit the brace 10 section intothe hook portion.

WALLACE J. S. JOHNSON.

References Cited in the file of this patent UNITED STATES PA'I'ENTSNumber Number Number Name Date Mead May 10, 1887 Weinbush Aug. 7, 1894Schrader May 11, 1897 Lillow Jan. 8, 1907 McLeran Jan. 28, 1913Wendbladh Apr. 15, 1924 Burt Oct. 4, 1932 Huthsing Nov. 13, 1934 DuganNov. 29, 1939 Block Dec. 1, 1942 Roney et a1 Jan. 19, 1943 Picone Apr.29, 1947 FOREIGN PATENTS Country Date Great Britain July 29, 1938

